scholarly journals Synthesis of Low Melting Temperature Aliphatic-Aromatic Copolyamides Derived from Novel Bio-Based Semi Aromatic Monomer

Polymers ◽  
2018 ◽  
Vol 10 (7) ◽  
pp. 793 ◽  
Author(s):  
Syang-Peng Rwei ◽  
Palraj Ranganathan ◽  
Whe-Yi Chiang ◽  
Yi-Huan Lee
Keyword(s):  
Melting Temperature ◽  
Average Molecular Weight ◽  
Weight Ratio ◽  
Sebacic Acid ◽  
Aromatic Polyamide ◽  
Polyamide 6 ◽  
Condensation Process ◽  
Weight Content ◽  
Human Body Temperature ◽  
Aromatic Monomer

This work investigated the synthesis of a novel low melting temperature polyamide 6 (PA6) copolyamide (PA6-BABT/SA) with different aliphatic/aromatic units weight content using a melt poly-condensation process. The bio-based aromatic N1,N4-bis(4-aminobutyl) terephthalamide diamine (BABT) and long-chain aromatic polyamide salt (BABT/SA, salt of BABT, and sebacic acid), components used for the synthesis of copolyamides, were obtained from bio-based monomers. For the first time, the pertinent BABT/SA aromatic polyamide salt was isolated as a white solid and completely characterized. By varying the weight ratio of BABT/SA salt, a series of copolyamides with different molecular weights and physical properties were prepared. The aromatic BABT/SA salt disrupted crystallization of the final copolyamides and lowered the onset of melting. The Fourier transform infrared spectroscopy and X-ray diffraction results indicated a steady decrease in the degrees of crystallinity with increasing BABT/SA salt segment ratio. Furthermore, compared to neat PA6, the obtained PA6-BABT/SA copolymers possessed a similar thermal stability and high transparency, but lower glass transition temperature around human body temperature. The PA6-BABT/SA copolymers with number-average molecular weight ≥30,000 Da presented good mechanical properties, specifically showing excellent tensile strength and elongation at break up to 105.2 MPa and 218.3%, respectively.

scholarly journals Effects of K2CO3 Addition on Inclusions in High-Carbon Steel for Saw Wire

2018 ◽  
Vol 37 (8) ◽  
pp. 701-709 ◽  
Author(s):  
Liangjun Chen ◽  
Weiqing Chen ◽  
Yang Hu ◽  
Zhaoping Chen ◽  
Yingtie Xu ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Melting Temperature ◽  
High Carbon Steel ◽  
Weight Ratio ◽  
New Method ◽  
Graphite Tube ◽  
Resistance Furnace ◽  
High Carbon ◽  
Slag Refining ◽  
Addition Amount

AbstractIn order to avoid the formation of crack initiation sites, inclusions in high-carbon steel for saw wire are strictly required to have excellent deformability. However, it is hard to achieve this goal with only conventional inclusion softening art, such as Si-Mn deoxidation and low basicity top slag refining. Therefore, a new method should be put forward to enhance the deformability of inclusions. Low melting temperature inclusions are widely considered to have good deformability, hence, adding K (potassium) into inclusions may become a potential new method to better enhance the deformability of inclusions due to the pronounced effect of K2O on lowering the melting temperature of inclusions. In the present study, the influences of Fe/K2CO3 (weight ratio), K2CO3 addition amount and reaction time on inclusions were investigated by using a graphite tube resistance furnace. Through this study, a solution to adding K into inclusions effectively by K2CO3 addition was developed and the melting temperature of inclusions was significantly reduced. In addition, the reaction mechanism between K2CO3/slag/steel/inclusion was deduced and the relation between deformability and crystallinity of inclusions was also briefly discussed.

scholarly journals Investigation into fibre orientation and weldline reduction of injection moulded short glass-fibre/polyamide 6-6 automotive components

2019 ◽  
Vol 33 (12) ◽  
pp. 1603-1628
Author(s):  
Sarah Mosey ◽  
Feras Korkees ◽  
Andrew Rees ◽  
Gethin Llewelyn
Keyword(s):  
Glass Fibre ◽  
Fibre Orientation ◽  
Weight Ratio ◽  
Polyamide 6 ◽  
Processing Parameters ◽  
Material Strength ◽  
Reinforced Polymers ◽  
Automotive Components ◽  
Glass Fibre Reinforced ◽  
Component Failures

Due to the increasing demands on automotive components, manufacturers are relying on injection moulding components from fibre-reinforced polymers in an attempt to increase strength to weight ratio. The use of reinforcing fibres in injection moulded components has led to component failures whereby the material strength is hampered through the formation of weldlines which are also a problem for unreinforced plastics. In this study, an industrial demonstrator component has the injection locations verified through a combination of fibre orientation tensor simulation and optical microscopy analysis of key locations on the component. Furthermore, the automotive component manufactured from 30% glass fibre–reinforced polyamide 6-6 is simulated and optimized through a Taguchi parametric study. A comparison is made between the component, as it is currently manufactured, and the optimum processing parameters determined by the study. It was found that the component can be manufactured with roughly 7.5% fewer weldlines and with a mould fill time 132 ms quicker than the current manufacturing process.

Crystallization Behavior of Polyamide 6 Prepared from a Phenol/Dichloroethane Mixed Solvent

2013 ◽  
Vol 834-836 ◽  
pp. 272-275
Author(s):  
Yu Ling Lai ◽  
Hung Pang Feng ◽  
Ching Yeh Tung ◽  
Tzu Ming Wu ◽  
Tien Wei Shyr
Keyword(s):  
Differential Scanning Calorimeter ◽  
Crystallization Behavior ◽  
Mixed Solvent ◽  
Polymer Concentration ◽  
Weight Ratio ◽  
Polyamide 6 ◽  
Diluted Solution

In this work, bulk polyamide 6 (PA 6) polymer was dissolved in the mixed solvent of phenol and dichloroethane with a weight ratio of 3:2 as a diluted solution. PA6 films were prepared from the diluted solution with varied polymer concentration. The crystallization and melting behaviors of the PA 6 films were studied using a differential scanning calorimeter. Results show that the ability of crystallization of the PA 6 films was obviously lower than that of the bulk PA 6 polymer. The effect of mixed solvent on the crystallization behavior of the PA 6 films is obvious.

Preparation and characterization of high molecular weight poly(trimethylene terephthalate) by solid-state polymerization

e-Polymers ◽  
2011 ◽  
Vol 11 (1) ◽  
Author(s):  
Kim Seok Hoon ◽  
Kim Joon Ho
Keyword(s):  
Molecular Weight ◽  
Reaction Time ◽  
Solid State ◽  
High Molecular Weight ◽  
Melting Temperature ◽  
Average Molecular Weight ◽  
Pellet Size ◽  
Solid State Polymerization ◽  
Trimethylene Terephthalate ◽  
High Molecular Weight Poly

AbstractSolid-state polymerization has been widely used to prepare high molecular weight poly(ethylene terephthalate). Solid-state polymerization is generally carried out by heating solid, melt-phase-polymerized polymer below its melting temperature but above its glass transition temperature. Solid-state polymerization of poly(trimethylene terephthalate)(PTT) is not an independent process but rather an additional process with respect to melt polymerization that is used when PTT of a higher molecular weight is required. Two kinds of commercial PTT chips were polymerized in the solid state to prepare high molecular weight PTT, which were characterized by end group contents, molecular weight, thermal analysis and X-ray diffraction. In the solid-state polymerization of PTT, the overall reaction rate was governed by the reaction temperature, reaction time and pellet size. The content of carboxyl end groups was decreased during the solid-state polymerization with increasing reaction time and temperature. The melting temperature and crystallinity of solid-state-polymerized PTT were higher at longer times and higher temperatures of polymerization. The activation energy for the solid-state polymerization of PTT was in the range of 24~25 kcal/mol for each chip. Through the solid-state polymerization of commercial PTT chips, we could get high molecular weight polymers up to an intrinsic viscosity value of 1.63 dl/g, which is equivalent to about a 117,000 weight-average molecular weight.

Silicon Quantum Dots-Carbon Nanotube Composite as Anode Material for Lithium Ion Battery

2013 ◽  
Vol 1540 ◽  
Author(s):  
Lanlan Zhong ◽  
Andi Xie ◽  
Lorenzo Mangolini
Keyword(s):  
Discharge Capacity ◽  
Silicon Nanoparticles ◽  
Electrode Materials ◽  
Active Material ◽  
Weight Ratio ◽  
Lithium Ion ◽  
Aliphatic Chain ◽  
Deposition Technique ◽  
Weight Content ◽  
Vapor Deposition Technique

ABSTRACTSilicon is a very promising material for anodes of lithium ion batteries. It exhibits a high theoretical capacity of 3579 mAh/g. However, during the lithiation and de-lithiation, silicon materials experience up to a 300% volume change, leading to poor cyclability [1-2]. Research shows that reducing the silicon particle size can mitigate this problem. Carbon nanotubes (CNTs) function well as electrode materials in electrolytic cells because of their high electrical conductivity and surface area. In this work, we combine silicon nanoparticles (Si NPs) and CNTs as anode materials. Si NPs are generated using a plasma-enhanced chemical vapor deposition technique and their surface is modified with a 12-carbon long aliphatic chain to impart solubility in non-polar solvents. They are applied onto a nanotube-based layer using a wet-phase deposition technique. SEM and TEM analysis confirm that they form a conformal coating onto the nanotube surface. The CNTs - Si NPs composite active material is tested in half-cells where lithium foil acts as counter electrode. We have achieved an average of 810 mAh/g discharge capacity for composites with a CNTs to Si NPs weight ratio of 1:1. We expect to be able to increase the discharge capacity by increasing the Si NPs weight content.

scholarly journals Preparation and characterisation of photocatalytic pigments for architectural mortar based on ultramarine blue

2019 ◽  
Vol 93 (3) ◽  
pp. 714-721 ◽  
Author(s):  
Estíbaliz Aranzabe ◽  
Miren Blanco ◽  
Amaia M. Goitandia ◽  
Karmele Vidal ◽  
María Casado ◽  
...  
Keyword(s):  
Sol Gel ◽  
Weight Ratio ◽  
Photocatalytic Properties ◽  
Blue Pigment ◽  
Building Sector ◽  
Ultramarine Blue ◽  
Weight Content ◽  
Coating Formation ◽  
Anatase Nanoparticles ◽  
Architectural Mortar

Abstract Architectural mortar is used in the building sector when aesthetic surface value is required and therefore, these surfaces present a great potential to be used as a solution for the reduction of atmospheric pollution. In the present work, an inorganic ultramarine blue pigment has been modified to provide the mortars with colour and photocatalytic properties, simultaneously. To modify the pigment, a sol–gel coating based on titanium n-butoxide precursor has been applied on its surface. The influence of different parameters affecting the coating formation, such as the pH and titanium weight content of the sol–gel reactants, has been studied. Moreover, the formation of a coating on the pigment’s surface with several amounts of TiO2 anatase nanoparticles has also been explored. A pigment with better photocatalytic properties has been obtained at pH = 12 applying a coating based on titanium n-butoxide precursors (Ti precursor/pigment weight ratio = 0.5) with 2 wt.% of titania anatase nanoparticles, maintaining the original pigment colour. Moreover, mortars with the new pigment present higher flexural strength and similar compressive strengths than non-modified mortars ensuring the applicability of the pigment in the building sector.

scholarly journals Assessment of Fiber Orientation on the Mechanical Properties of PA6/Cellulose Composite

2020 ◽  
Vol 10 (16) ◽  
pp. 5565
Author(s):  
Pruthvi K. Sridhara ◽  
Fabiola Vilaseca
Keyword(s):  
Fiber Orientation ◽  
Flow Direction ◽  
Weight Ratio ◽  
Polyamide 6 ◽  
Pulp Fibers ◽  
Cellulose Pulp ◽  
Low Thermal Expansion ◽  
Oriented Samples ◽  
The Matrix ◽  
Cellulose Composite

Cellulose is being considered as a suitable renewable reinforcement for materials production. In particular, cellulose based composites are attracting global interest for their unique and intrinsic properties such as strength to weight ratio, dimensional stability and low thermal expansion and contraction. This article investigates the preparation of cellulose pulp fibers with polyamide-6 (PA6) polymer and the effect of fiber orientation within the matrix on the final properties of the biocomposite. Cellulose pulp fibers were melt compounded with PA6 using a thermo-kinetic mixer. Different formulations were prepared and the compounds were manufactured into test samples by injection molding. Mechanical characterization revealed that elastic modulus and the flexural properties increased linearly with the fiber composition. The effect of fiber orientation was examined from square samples out of which individual specimens were cut at different directions with respect to the flow direction. The contributions related to fiber content and effect of fiber orientation on the tensile properties assessed lent positively towards parallel oriented samples (0°) with respect to flow direction. Furthermore, the cellulose network within the biocomposite revealed the superior interfacial properties between the cellulose and PA6 matrix when observed under a scanning electron microscope.

Poly(glycerol-sebacate)/poly(caprolactone)/graphene nanocomposites for nerve tissue engineering

2018 ◽  
Vol 33 (5) ◽  
pp. 529-542 ◽  
Author(s):  
Shirin Ghafaralahi ◽  
Mehdi Ebrahimian-Hosseinabadi ◽  
Anousheh Zargar Kharazi
Keyword(s):  
Mechanical Properties ◽  
Cell Attachment ◽  
Weight Ratio ◽  
Sebacic Acid ◽  
Biological Properties ◽  
Attenuated Total Reflection ◽  
Nerve Tissue ◽  
Positive Role ◽  
Nerve Guidance Conduit ◽  
Poly Caprolactone

In this study, mechanical, electrical, physical, and biological properties of polymeric matrixes comprising poly(glycerol-sebacate) (PGS) and poly(caprolactone) (PCL) with various weight ratio of PGS:PCL (1:3 and 1:1) were evaluated in order to apply as nerve guidance conduit. For this purpose, synthetic PGS pre-polymer was acquired using poly-condensation of glycerol and sebacic acid and characterized by attenuated total reflection-fourier transformed infrared (ATR-FTIR) and X-ray diffraction (XRD) spectroscopies. Furthermore, the effect of 1 wt% graphene (Gr) Nano sheets incorporation as filler, was investigated. Blending PGS with PCL significantly improves the hydrophilicity of the samples and improves cells attachment; however, their mechanical properties decreased dramatically. Presence of Gr within the polymeric matrix, significantly increased elastic modulus and tensile strength, which is possibly attributed to its superior mechanical properties and high aspect of ratio. Moreover, aforementioned polymeric matrixes, turned to conductive membranes by addition of Gr, which affected drastically on their biological properties; that way, 3, 4, 5-dimethylthiazol-2, 5-diphenyl tetrazolium bromide assay elucidated that only addition of 1 wt% Gr to the polymeric films resulted in improved cell survival and cell attachment for 7 days of cell seeding. In addition, cell attachment was enhanced considerably by increasing PGS up to 50 wt%, due to positive role of PGS on contact angle reduction. Therefore, the nano-composite film (50PGS-50PCL-1Gr) can be a promising substrate to use as a nerve guidance conduit.

Preparation and Characterization of Plasma-Treated Porous Poly(glycerol sebacate) Scaffolds

2013 ◽  
Vol 747 ◽  
pp. 182-185
Author(s):  
Tharinee Theerathanagorn ◽  
Boonlom Thavornyutikarn ◽  
Wanida Janvikul
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
Photoelectron Spectroscopy ◽  
Average Molecular Weight ◽  
Sebacic Acid ◽  
Angle Measurement ◽  
Porous Scaffolds ◽  
Hydroxyl Groups ◽  
Condensation Polymerization ◽  
Water Contact

In this study, poly (glycerol sebacate) (PGS) was initially synthesized via condensation polymerization of glycerol and sebacic acid at equimolar ratio (1:1) at 130°C for 24 h. The number average molecular weight (Mn) of the resulting polymer determined by gel permeation chromatography (GPC) was about 2800 g/mol. Porous PGS scaffolds were subsequently prepared by a particle-leaching technique. NaCl was added into the polymer at 60-90% w/w; the mixtures were cured in Teflon molds at 140°C for 16 h. The porous scaffolds were further subjected to surface treatment with low pressure oxygen plasma to increase surface carboxyl and hydroxyl groups and thereby enhance hydrophilicity of PGS scaffold surface. The surface morphology and wettability of both untreated PGS and plasma-treated PGS scaffolds were comparatively determined by scanning electron microscopy (SEM) and water contact angle measurement, respectively. A considerable decrease in water contact angle was observed on the PGS scaffolds after the plasma treatment. The surface chemistry, mechanical strength and degree of swelling of the PGS scaffolds were also assessed by X-ray photoelectron spectroscopy (XPS), dynamic mechanical analysis (DMA) and swelling measurement, respectively.

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